This time, the 31 churchgoers on the bus came from a Presbyterian church south of Seoul, as they were touring biblical sites in commemoration of the church’s 60th anniversary of its founding.

“No one has claimed responsibility for the blast, which bore the hallmarks of attacks blamed on al-Qaida-linked militant groups that have been battling government forces in Sinai’s restive north for years,” the AP reports.

On Sunday, the church group was about to enter Israel from the Egyptian border town of Taba after visiting an ancient monastery in Sinai. The group had left South Korea last Monday on its 12-day tour of Israel, Egypt, and Turkey.

”My mother was a devout Christian,” the dead church member’s daughter, surnamed Yoon, told South Korea’s Yonhap news agency. ”I don’t know how such a thing could happen. I don’t know how to react to this.”

South Korea has long been known for its zeal for mission work, with nearly 30 percent of the country’s population claiming Christianity. They have 20,000 missionaries in 177 countries, ranking No. 6 in the world for sending the most missionaries. Some Korean Christian leaders see the existing travel bans not as a hindrance to missions work, but an opportunity to “focus Korean missions in areas where missionaries are more accepted and more likely to be successful,” CT reported.